Carburetor



Feb. 16, 1932. F. H. HEITGER CARBURETOR Filed Nov. 9, 1929 :5 sheets-sheet 2 NVE/Mlm@ llillllllllnlllllllll .Illllllflallnlllllul Ji /V// Feb., 16, 1932. F1 H, HEM-GER 1,845,662

CARBURETOR Filed NOV. 9, 1929 3 Sheets-Sheet 3 Patented Feb. is, 1932 UNITED STATES FRANK H. HEITGER, F FLINT, MICHIGAN CARBURETOR Application med November 9, 1929. Serial No. 405,924.

This invention relates to carburetors for internal combustion engines. ,Y

lit is an object of this invention to provide a carburetor incorporating improved means for supplying an accelerating charge of fuel for sudden acceleration and to maintain the accelerating fuel feed for a predetermined interval after the opening movement of the carburetor throttle has reached its maximum 1o as determined by the operator. It frequentlyA occurs that the operator may desire to accelerate rapidly Without necessarily moving the throttle to its maximum wide open position, and with such a partial opening to a I5 predetermined point the present invention will provide and maintain the eXtra supply of accelerating fuel.

lt is also an object of this invention to provide an accelerating device adapted to place a supply of fuel in a well under superatmospheric pressure, wherein the accelerating piston is adapted to close a normally'open vent which acts as an air bleed into the well to normally produce an economical mixture, the closing of the vent serving to give a richer mixture for producing maximum power. The most economical mixture is usually about 1G to 1, while the mixture producing the maximum power is in the neighborhood of 12% so to l.

lt is a further object of this invention to provide an accelerating device comprising a free piston yieldingly 'urged toward the fuel inan auxiliary reservoir and moved away therefrom by suction communicated to one side of the piston from above the carburetor throttle so that the manifold suction of a running engine will be sufficient to lift the piston. A vent controlled by the throttle movement serves to break the suction and permit the piston to drop.

Other and further important objects of this invention will be apparent from the disclosures in the specification and accompanying drawings.

The invention (in a preferred form) is illustrated on the drawings and hereinafter' more fully described.

n the .drawings Figure l is a side elevation of a carburetor embodying the features of this invention. y

Figure 2 is a fragmental section on the line II-I of Figure 1 through the suction control valve and 'passages Figure 3 is a view of the control valve.

Figure 4 is a fragmental section on the line IV-IV of Figure 2.

Figure 5 is an enlarged section on the line VV of Figure 4 showing the acceleration fuel supply arangement.

Figure 6 is a modied form of Figure 5.

Figure 7 is a partly diagrammatic section showing the relationship of the various fuel chambers and passages.

As shown on the drawings:

A carburetor body 10 is provided with the customary mounting flange 11, ioat bowl 12, air inlet 13, throttle valve shaft 14 and throttle lever 15. The present invention is embodied in a vertical tubular boss 16 ap- 'm plied to the side of the carburetor body and which is supplied with fuel through a port 17, shown in dotted lines in Figure 5, which leads from the nozzle fuel supply passages of the conventional carburetor. By means of the port 17 fuel normally stands inthe tubular member at substantially the same level'as in the float bowl, although this fuel may feedback to the nozzle when demands are made thereon in excess of the capacity so of the normal carburetor fuel passages, as will hereinafter be more particularly described.

The tubular member 16 extends substantially the full height of the carburetor body, its lower section 18 being enlarged slightly below the fuel level 19 therein to form an auxiliary reservoir which contains a central stud 20 having a passaged head 21 making sealing Vcontact with the normal diameter 22 of the tube above the fuel level. The shank of this stud may be made of different sizes to vary the fuel capacity of the auxiliary reservoir 18. The head 21 of the stud serves as a stop for a cup-like piston 23, which is slidable in the upper part 22 of the tube, being urged downwardly by a spring 24 ositioned between the piston and the close upper end 25 of the tube 16. A spring pilot is provided in the form of a tube 26, which L sage 27 in a boss 28, one end 29 of this passage opening into the carburetor outlet passage 30 above the throttle location, and lthe other end 31 of the passage 27 extending to the outside of the boss, being covered by a valve plate 32. The valve plate is pivoted at 33 and apertured at 34; being yieldingly held in a position to close the passage end 31 by a spring 35. The throttle lever is provided with a fin 36 adapted to strike and rotate the valve plate into a position such that the aperture 34 therein exposes the passage end 31 when the throttle has been partially opened.

In the modification of Figure 6, the tube 16 is not enlarged `below the simply a straight cylinder 37, a short stud 38, having a passaged head 39 being so positioned as to allow further downward movement of the piston 23 to the position shown in the figure, to that in this form of the invention the piston serves to practically empty the fuel from'the chamber 40v corresponding to the auxiliary reservoir 18.

The combination of the second form of this invention with the fuel chambers and passages of the carburetor shown in Figure 1, is shown in Figure 7.wherein the auxiliary fuel reservoir is turned at right angles to lie in the central section of the carburetor proper. In the form shown, fuel, at the level 19 in the fioat chamber 12, feeds past a regulating needle valve 50 into a passage 51 lead- 52 below a main fuel discharge nozzle 53. The fuelpassage 17, previously referred to, opens into this chamber 52 and draws fuel therefrom or returns fuel thereto in accordance with the movements of the piston 23.

An idling fuel nozzle 54 is directly supplied with fuel through a passage 55 and discharges into an air bypass passage 56 leading past the venturi 57 to a discharge port 58 aligned with the edge of the throttle dise 59 when the latter is in a closed position. An air bleed 60 adjacent the port 58 is controlled by an adjustable valve the head of which is shown in Figure 1.

Both forms of the invention have the lower chambers 18 and 40 vented. In the form of Figures 4 and 5, a side vent 41 has a plug 42 therein which carries a light ball 43 adapted to be lifted by pressure within the reservoirto seal the vent, which is otherwise normally open and serves as an air bleed into the reservoir 18. In Figure 6, the plug 42 and ing to a chamber ball 43 are mounted as a vent on the top of a well 45 supplied by a passage 46 from the chamber 40.

IIn both forms of the invention a second air bleed vent 47 is formed in the wall of the tube 16 just beneath the bottom of the piston when the latter is in its uppermost position, so that the initial downward movement of the piston uel level, but .is

closes the vent and thus allows compression of the air above the fuel which compressed air in turn ejects the fuel through the passage 17 whence it is discharged through the normal nozzle system of the carburetor.

In order to'provide a richer mixture for starting or warming up a cold engine, I provide a thermostatie kor bi-metallic strip 48 so positioned as to close the vent when bent inwardly under the infiuence of low temperatures, the strip being shown in its straight position as for operation at normal temperatures. The closing of this vent 47 by either the piston or the thermostatic strip 48 cuts off the air bleed and, therefore, gives a richer mixture in the order of 121/2 to 1. During idling, the fuel will stand at the level 19 in the reservoir and chamber since the fuel supply to the normal fuel system of the carburetor will be ample for all demands thereon.

However, as the throttle is opened up to one third or one half throttle, the demand on the normal fuel feeding system increases and the reservoir or chamber is free to empty due to the suction in the normal fuel system. At the same time, the air bleed vents 47 and 41 feed `air which mixes with the fuel to lean out the final mixture for the desired economy range of normal operation.

After the throttle is opened beyond the one third or one half point the fin on the throttle lever moves the valve 34 to uncover the passage end 31, thus breaking the suction that holds up the piston, so that the piston drops cutting off the vent 47 which alone results in a richer final mixture. The vents 41 are always open during normal operation. After the piston drops, it is stopped by the head of the stud in both forms of the inventlon.

When thethrottle is suddenly opened, as for accelerating purposes, the fin on the throttle lever strikes the edge of the valve 34 to uncover the passage end 31, thus destroying the vacuum which holds up the piston, and allows the piston to be forcedv down by its spring. The downward movement of the piston closes the vent 47 and compresses the trapped air above the fuel level. -This superatmospheric pressure acts on the fuel in thel auxiliary reservoir by way of the passages in the stud head 21 forcing fuel from the reservoir into the normal fuel passages feedthe chamber to the nozzle feeding passages. 13

' lag in fuel delivery due to the changing suction acting on the normal fuel nozzle.

I am aware that numerous details of coustruction may be varied through a wide range without departing from the principles of this invention, and I, therefore, do not purpose limiting the patent granted, otherwise than necessitated by the prior art.

I claim as my invention:

l. In a carburetor for internal combustion engines including the normal fuel feeding system therefor, an auxiliary fuel reservoir adapted to be partially lled with fuel from the fuel feeding system of the carburetor, a free piston slidablein said reservoir above the fuel therein, means for applying engine` suction to said piston to normally sustain the piston in the upper portion of said reservoir, means for interrupting said suction to release said piston whereby the downward movement thereof will discharge the fuel from said reservoir into the normal fuel feeding system of the carburetor, and a vent opening into said reservoir immediately beneath the uppermost position of said piston, said vent forming an'air bleed into said reservoir which is cut olf by the downward movement of said piston.

2. In a carburetor for internal combustion engines including 4the normal fuel feeding,r system therefor, an auxiliary fuel reservoir adapted to be partially filled with fuel from the fuel feeding system of th e carburetor, a free piston slidable in said reservoir above the fuel therein, a spring acting to drive said piston downwardly in said reservoir, means for applying engine suction to said piston 'to normally sustain the piston in the upper portion of said reservoir, and means for interrupting said suction to release said piston whereby the downward movement thereof will discharge the fuel from said reservoir into the normal fuel feeding system of the carburetor, and a vent opening into said reservoir immediately beneath the uppermost position of said piston, said vent forming an air hleefl into said reservoir which is cut off by the downward movement of said piston.

3. In a carburetor for internal combustion engines including the normal fuel feeding system therefor, an auxiliary fuel reservoir adapted to he partially filled with fuel from the fuel feeding system of the carburetor, a free piston slidable in said reservoir above the fuel therein, means for applying engine suction to said piston to normally sustain the piston in the upper portion of said reservoir,

'said piston and restricting the means for interrupting said suction to release said piston whereby the'downward movement thereof will discharge the fuel from said reservoir into the normal fuel feeding Vsystem of the carburetor, and a vent opening into said reservoir immediately beneath the uppermost position of said piston, said vent forming an air bleed into said reservoir which is cut oil by the downward movement of said piston, and thermostatic means for closing said vent below a predetermined temperature.

4. In a carburetor for internal combustion engines including the normal fuel feeding system therefor, an auxiliary. fuel reservoir adapted to be partially lled with fuel from the fuel feeding-system of the carburetor, a free piston slidable in said reservoir above the fuel therein, a spring acting to drive said piston downwardly in said reservoir, means for applying engine suction to said piston to, norma 1y sustain the piston in the u per portion of said reservoir, and means or interrupting said suction to release said piston whereby the downward movement thereof will discharge the fuel from said reservoir into the normal fuel feeding system of the carburetor, and a vent opening into said reservoir immediately beneath the up ermost position of said piston, said vent orming an air bleed into said reservoir which is cut olf by the downward movement of said piston, and thermostatic means for closing said vent below a predetermined temperature.

5. In a carburetor including the throttle and the normal fuel feeding system there for, a closed fuel reservoir partially filled from said fuel feeding system, a piston slidably mounted in said reservoir, replaceable means in said reservoir forming a stop for said piston and restricting the fuel capacity of said reservoir, a conduit from the interior of the carburetor above the throttle to the top of said reservoir above said piston whereby suction above the throttle is normally imposed on said piston to hold it in its uppermost position, a port communicating with said suction' conduit, and means normally closing said-port and-coacting with said port upon a predetermined movement of the throttle whereby the suction on said piston will be released to permit downward movement thereof.

6. In a carburetor including the throttle and the normal fuel feeding system therefor, a closed fuel reservoir partially filled from said fuel feeding system, a piston slidably mounted in said reservoir, replaceable means in said reservoir formin a stop for el capacity lun of said reservoir, a conduit from the interior will be released to permit downward movement thereof, and a vent opening into said reservoirimmediately beneath the uppermost position of said piston, said vent forming an air bleed into said reservoir which is cut off by the downward movement of said- `piston.

7 In a carburetor including the throttle and the normal fuel feeding system therefor, a closed fuel reservoir partially filled from said fuel feedingV system, a piston slidablymounted in said reservoir, replaceable means in. said reservoir formin a stop for said piston and restricting the uel capacity of said reservoir, a conduit from the interior of the carburetor above the throttle to the top of said reservoir above said piston whereby suction above the throttle is normally imposed on said piston to hold it in its uppermost position, a port communicating with said suction' conduit, and means normally closing said port and coacting with said port upon a predetermined movement of the throttle whereby the-suction on 'said piston will be released to permit downward movement thereof, a vent opening into said reservoir immediately beneath the u permost position-of said piston, said vent orming an air bleed into said reservoir which is cut o by the downward movement of said piston, and thermostatc means for closing said vent below a predetermined temperature.

8. In a carburetor including the throttle and the normal fuel feeding system therefor, a closed fuel reservoir partially filled from said fuel feeding system, a piston slidably mounted in said reservoir, replaceable means in said reservoir formin a stop for said piston and restricting the uel capacity of said reservoir, a conduit from the interior of the carburetor above the throttle to the top of said reservoir above said piston whereby suction above the throttle is normally imposed on said piston to hold it in its uppermost position, a port communicating with said suction conduit, and means normally closing said port and coacting with said port u on a predetermined movement of the thrott e whereby the suction on said piston` will be released to permit downward movement thereof, an auxiliary reservoir communicating with the first mentioned reservoir, and an air bleed into said last mentioned reservoir.

9. In a carburetor including the throttle and the normal fuel feeding system therefor, a closed fuel reservoir partially filled from said fuel feedin system, a piston slidably mounted in sai reservoir, replaceable with said suction conduit, means normally closing said port and coacting with said port upon a predetermined movement of the throttle whereby the suction on said piston will -be released to permit downward movement thereof, an auxiliary reservoir communicating with the first said mentioned reservoir, an air bleed into said last mentioned reservoir, and means for preventing the discharge of fuel through said air bleed.

10. In a carburetor for internal combustion engines including the normal fuel feeding system therefor, an' auxiliary fuel reservoir in communication with the fuel feeding system of the carburetor, a free piston slidable in said reservoir, means for applying engine suction to said piston to normally sustain the piston in the upper portion of said reservoir above a predetermined degree of engine suction, and a vent opening into said reservoir beneath the'uppermost position of said piston, said vent forming an air bleed into said reservoir which is cut off by the downward movement of the piston.

11. In a carburetor for internal combustion engines including the normal fuel feeding system therefor, an auxiliary fuel reservoir incommunication with the fuel feeding system of the carburetor, a free piston slidable in said reservoir, a spring acting against said piston to drive the same downwardly, means for applying engine suction to said piston to normally sustain the piston in the upper portion of said reservoir above a predetermined degree of engine suction, and a Vent opening into said reservoir beneath the uppermost position of said piston, said vent forming an air bleed into said reservoir which is cut off by the downward movement of the piston.

In testimony whereof I have hereunto subscribed myname at. Flint, Genesee County,

Michigan.

FRANK II. HEITGER. 

